Amazon Web Services (AWS), which offers a reliable bulk email service called AWS SES. It had a hard bounce rate of 10%. A hard bounce occurs when an email can’t be delivered for permanent reasons, like if the email address is fake, the domain isn’t valid, or the recipient’s server won’t accept emails. So, if out of 1000 emails sent, 100 were fake or invalid and bounced, AWS SES would block your SES service by temporarily suspending sending privileges.
Here’s how AWS SES works whenever a Email is bounced: